It is not necessary for a @RequestScoped bean to implement the java.io.Serializable interface, nor is it necessary to define a serialVersionUID. It also means that the transient keyword is not necessary on @ManagedProperty injection properties.

The reason why this happened is because FACES-1543 introduced a @ViewScoped ApplicantViewBean class (which needs to be Serializable) with commit 3f6ca5c2 but we neglected to remove the serializable functionality from the ApplicantBackingBean.